Carburetor for internal combustion engines



F. DAY

CARBURETOR FOR INTERNAL COMBUSTION ENGINES .3 Sheets-Sheet 1.

Filed Dec. 18, 1928 ATTO'RNEY Oct. 6, 1931.

F.- DAY CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Dec. 18, 1928 3 Sheets-Sheet 2 INVENTOR flggd Jay ATTORNEY Oct. 6, 1931. F. DAY

CARBURE'TOR FOR INTERNAL COMBUSTION ENGINES Filed Dec. 18, 1928 3 Sheets-Sheet 5 I m mw INVENTOR 'Frerl flay ATTORNEY Patented @ct. 6 1931 PATENT OFFICE ran]; DAY, or'nLonsrnasourri nAKo'rA CARBURETOR FOR INTERNAL coMBUs'r'roiv enemas Application filed December 18, 1928. Serial No. 326,839,

My invention relates to carburetors for internal combustion engines. An object of the invention is to provide a carburetor wherein the use of the usual ,6 vacuum tank is eliminated, and which will operate in conjunction with a gasoline tank arranged below or above the carburetor.

The invention further provides a carburetor wherein liquid is admitted into a float chamber in proportion to its consumption by an internal combustion engine under the influence of vacuum created by the engine.

Itis another object of my invention to provide a carburetor having a main airsupply controlled by an automatic valve which is cushioned in its opening and closing movements and is thereby held against vibratory movements incident to such opening and closing.

L With the preceding and other objects and advantages in mind, the invention consists in the novel combination-0f elements, constructions and arrangement of parts to be hereinafter specifically referredto, claimed 5 and illustrated in the accompanying drawings, wherein:

Figure 1 is' a verticalsectional view of a carburetor embodying my invention,

Figure 2 is a horizontal section taken on 130 line 2-2 of Figure 1,

Figure 3; is a perspective of the elements constituting the float mounting embodied in the invention,

Figure 4 is a-verti'cal section taken on line M of Figure 1,

Figure 5 is aside elevation of theinvention, 1 c

Figure 6 is a vertical sectional'view of the same taken'on line 6-6 of Figure 5,

Figure 7 is a horizontal section on the line 7-7 of Figure 6, 1 a Y i Figure 8 is a perspective of the spray or atomizer embodied in the invention,

Figure 9 is a horizontal sectional viewtaken on line 9-9 of Figure 1,

Figure 10 is a similar View taken on line 10-10 of Figure 1,

Figure 11 is a detail elevation of parts of the invention, and

Figure 12 is a fragmentary longitudinal sectional view of a motor vehicle equipped with my invention. I Referring to 'the invention in detail a circular casting5 formed with an upstanding settling or splash chamber 6 at one end is provided. 'A' vertically disposed mixing tube 7 is'cast with the inner face of the chamher and is'provided with lateral ears 8 at its upper end for connection with a conventional intake manifold 9, by means of fastenings 10. This mixing tube 7 is located centrally of the casting and has its lower end cast with a rectangular main air chamber 11 cast with the upper face of the circular casting. 'At a point diametrically opposite the chamber, the as mixing tube is formed with a circular laterally extending internally threaded collar 12, which at its lower side, is formed integrally with the upper face of the circular casting, and at its inner edge, integrally connects a the side walls of the main air chamber 11, as illustrated'in Figures 1 and 5. a i

For the purpose of conducting air into th main air chamber to be subsequently mixed with liquid fuel in the mixing'tube 7, a cylindrical open ended housing 13 is threaded into the collar and projects laterally with respect to the mixing tube. This housing 13 is graduated' in diameter'towards its inner end, and at itsouter end is provided with notches 14: for the reception of a blade or other implement for the purpose of attaching or detaching the housing from the internally threaded collar.

To automatically control the passage of air es through the open ended housing by the vacuum produced in the mixing chamber from theinternal combustion engine to which the carburetor is attached, an air control valve is provided comprising a horizontally '90 disposed stem 15 passing centrally through a relatively large inlet opening 16 formed in a wall 17 extending transversely across the open ended housing adjacent its inner end. This stem 15 has its inner end threaded into the lower end of the mixing tube, as at 18, while its outer end is formed with a piston head 19 which is located in advance of the opening 16 and is concentric with the walls of the housing. The piston head is received H 0 within a cylindrical hollow piston 20 having a removable plug or head 21 threaded into its forward end. To mount the hollow piston for longitudinal movement within the open ended housing, a sleeve 22 is formed with its rear wall and is slidable on the stem 15. A hollow frusto-conical valve element 23 surrounds the sleeve intermediate its ends and has its smaller end fixed to the sleeve so that the valve element will move longitudinally through the air inlet opening. At its large end the valve element is provided with an annular stop flange 24 which is normally urged against the inner face of the wall 17 by an expansible coil spring 25 having one end abutting the mixing tube and its opposite end engaged within the valve element. A groove 26 is provided in the outer face of the piston head 19 and the plug 21 for the purpose of receiving a blade or other suitable instrument when it is desired to apply or remove the stem 15 and the plug 21.

From the description thus far given it follows that the vacuum produced in the mixing tube from the intake manifold draws the valve element and hollow piston rearwardly against the action of the expansihle spring. This opening of the valve element is governed by the speed at which the internal combustion engine is operated. It will be observed that due to the compression of air between the ends of the hollow piston and the fixed piston head. incident to the movement of the hollow piston, the longitudinal movement of the valve element will be cushioned and therebv eliminate vibration to such valve element as the latter opens and closes. Due to the great volume of air passing into the open ended housing 13 the hollow piston will he urged longitudinally toward the conduit 7. Tn other words after the valve 24 has been unseated by the suction in the conduit 7 the air travelling through the open ended housing makes contact with the hollow piston and holds the same in a position where the valve 24 will remain unseated. It will he therefore seen that I utilize the air flowing into the carburetor to overcome the resistance of the spring 25.

Depend ng from the under face of the circular asting and surrounding a central internally threaded opening 27 therein is a cylnder 28 whose lower porti on is provided with liquid fuel inlet openings 29. The cylinder is received within a float chamber or bowl 330 which has its upper edges positioned against the under face of the circular casting at the edges of the latter. and is provided with a central opening 31 in its bottom which is surrounded by the lower end of the cylinder. The float chamber is further provided with a valve controlled drain a in its bottom. Received in the cylinder and projecting slightly below the float chamber is a cylindrical body 32 whose upper end stops short of the circular casting and is threadcdly cugaged with the interior of the cylinder, as at An annular flange 34 is provided on the lower end of the body, which supports the float chamber against the circular casting. At its upper end the cylindrical body is formed with a vertically extending discharge tube 35 which extends through the opening 27 and terminates at the lower end of the mixing tube 7. To permit liquid fuel to pass from the float chamber into the discharge tubc, a longitudinal bore 36, coaxial with the bore of the discharge tube, is provided in the cylindrical body and communi--- cates at its lower end with a transverse inlet opening 37 extending substantially the entire width of the body adjacent its lower end. The periphery of the cylindrical body is provided with a groove 38 which overlies the area of the cylinder having the inlet openings 29 so as to define a passage whereby the liquid fuel may pass from the bowl into the inlet opening 37. A needle valve 39 is threadedly engaged with the lower end of the cylindrical body and passes into the inlet opening 37 to govern the flow of liquid fuel to the bore 36. A suitable strainer 40 is received on the cylinder to strain the liquid fuel before it reaches the mixing tube.

For the purpose of allowing liquid fuel to pass into the float chamber, an inlet nipple 41 is cast upon the upper face of the circular casting at a point to one side of the air chamber 11 and receives one end of a sup ply pipe 42 which, in this instance, leads from a supply tank 43 arranged below the carburetor, as illustrated in Figure 12. At its inner end this inlet nipple communicates with an interiorly threaded opening 43?) in which a cylindrical valve cage 44 is threaded.

A reciprocable valve element 45, adapted to normally close an inlet opening 46 in the upper end of the valve cage, is received Within the latter for vertical movement therein. In order to normally maintain the valve element in raised or closed position, a circular hollow float 47 is received in the float chamber and surrounds the cylinder 28. The float is hingedly supported in the float chamber by means of (-oacting hinge elements 48 and 49, the former of which being fixed to the upper face of the float, while the latter is provided with a central opening 40 through which the valve cage passes. This hinge element 49 is clamped against the under face of the circular casting to support the float by a head 51 formed on the lower end of the valve cage. To hold the float against rotation, an upstanding tongue 52 is struck from the hinge element 49 and is engaged in a recess 53 in the under face of the circular casting, laterally of the valve cage. Normally the lower end of the valve element rests upon the float to maintain the valve element in closed position. However, when the float latter and has its lower end threadedly engaged therewith, as at Ra dially disposed a'i r'in let ports 56 are formed in the sleeve adjacent its lower end to permit air to pass between the discharge tube and sleeve and thence escape from the restricted upper end 57 of the sleeve, which is arranged above the upper end of the discharge tube and is coaxial therewith. Thus as theliquid fuel and air meet at the restricted end 57, the liquid fuel will be atomized and subsequently mixed with alarger volume of air that is continuously passing into the mixing tube from the open ended housing.

A vertically extending air bleed 61 is formed in the cylindrical body 32 and has one end communicating with the upper end of the cylinder 28, while its opposite end communicates with a lateral branch 62 in the lower end of the cylindrical body leading to the atmosphere. A needle valve 63 is threadedly engaged with the lower end of the bore 61 for controlling the lateral branch.

Communication between the float chamber and settling chamber 6 is had by way of an opening 66 provided in the circular casting.

' An L-shaped conduit 64a is attached to the upper end of the cylinder 28 and has communication therewith. The vertical leg of this conduit passes through the opening 66 and extends within the chamber 6.

Some of the air discharged into the cylinder 28, through the bore 61, passes into the radial ports 56 for atomization of the liquid fuel being discharged from the discharge tube 35, as above set forth. In addition, some of the air from the bore 61 passes upwardly around the exterior of the sleeve 54 for intermixing with the atomized fuel. For the purpose of directing this additional air upwardly around the exterior of the sleeve, a bushing 67 is threaded into the opening 27 and is formed with a restricted circular opening 68 at its upper end, whose walls lie close to the periphery of the sleeve 5%. todirect air along the periphery of'the sleeve where it will intermingle with the atomized liquic fuel. 7

To facilitate starting of the motor 69 with which the carburetor is associated, as illustrated in Figure 12, 'a reciprocable primer valve 70 is vertically movable in a longitudinal bore 71 provided in a vertically extending lateral enlargement 72 formed on one side of the chamber and opening into the float chamber. An air inlet port 7 8 is formed in the lower end of the enlargement 72 and communicates with the bore 7 1 so that upon raising of the valve, air will be permitted to pass into the float chamber by way of the port 78. The valve 70 is attached to a flexible vertically extending actuating rod 7a, which is encased in :a vertically extending coil spring 75, whose lower end is mounted within a recess 76 provided in the lateral enlargement 72 at the upper end of the bore 71. To hold the lower end of the coil spring within the recess,a clamping jaw '77 is provided on one side of the chamber, which is held in clamped engagement with the coil spring by a set screw 78 passing through the jaw and engaged with the walls :of the chamber. 'At its upper end the coil spring passes through a laterally extending perforated ear C 9 projecting from one of the ears 8. As illustrated in Figure 12, the coil spring 75 is connectedwith one end of a tubular guide 80 projecting from the automobile dash and a handle 81 is provided on the upper end of the :rod 74.

Tncident to the operation of an internal combustion engine to which the carburetor is attached, the valve 24 is moved inwardly "against the action of the coil spring 25 by suction created in the conduit 7. That is to say, the opening movement of the valve '24 is responsive to the vacuum in the conduit 7 and its opening movement is in proportion to the speed of the engine. Assuming the engine to be operating at a high speed, vacuum will be greater at the lowerend of the conduit 7 and the upper end of the atomizer ot'than at the circular opening 68. Due to the greater vacuum at this point, liquid fuel is drawn through the bore 40 in proportion to the engine speed. Instantaneous with a light downward movement of the float H,

the vacuum will be comnnmi'cated to the supply pipe 412 by way of the bore 40 and float chamber to draw liquid fuel into the latter. In other words, the amount of liquid fuel that passes through the bore 40 is continuously replaced in the float chamber byvacuum communicated o the float chamber through this bore;

While the engine is operating at slow speed vacuum is reduced in the float-chamber to act on the liquid fuel supply pipe 42 by :atmos- 'fp heric pressure communicated to the float chamber through the bore '61 and L-shapei l conduit 64a; 1 i

What is claimed is:

'1. In a carburetor, a liquid fuel reservoir, a conduit arranged above the same for communication with an internal combustion engine, means for conducting liquid fuel from the reservoir to the conduit, an open ended air inlet housing supported laterally of the conduit and communicating with the latter, v

a fixed piston supported within and longitudina'lly of said housing, a movable hollow piston received on the "fixed piston, a valve element connected to and movable with the hollow piston and controlling the passage of air through the housing, said movable piston being disposed forwardly of said valve and in the path of air passing through said housing, the valve element being actuated to open position by vacuum produced in the conduit, movement of the hollow piston towards either face of the fixed piston causing compression in the hollow piston whereby to eliminate vibration of the valve incident to the opening and closing movements of the latter.

2. In a carburetor, a mixing conduit for connection with the intake manifold of an internal combustion engine, means for discharging liquid fuel into the mixing conduit, an open ended air inlet housing supported to one side of the conduit and communicating therewith, a horizontally disposed piston supported from the conduit and projecting into the housing, a hollow longitudinally movable piston receiving the fixed piston and urged in one direction by air pressure flowing through the housing, and a resiliently seated valve element or controlling the passage of air from said housing to said conduit and connected to and movable with the hollow piston and operable to open position by. suction created in the mixing conduit from such intake manifold.

3. The combination with a carburetor, of an air supply housing supported at one side thereof and communicating therewith, a vacuum responsive Valve element controlling communication between the housing and carburetor, an expansible coil spring normally urging the valve element to closed position, and a piston connected to said valve element and movable therewith, said piston being disposed forwardly of said valve element in the path of air assing through said housing, whereby said air pass ing through said housing will urge the piston in a direction to unseat the valve.

4. The combination with a carburetor, of an air supply housing supportedat one side thereof and communicating therewith, a vacuum responsive valve element controlling communication between the housing and carburetor, and pneumatic cushioning means associated with said valve element to eliminate vibration thereto incident to opening and closing movement thereof, said means being disposed forwardly of said valve and in said air supply housing and including a piston connected to said valve and disposed in the path of air passing through said housing and movable longitudinally thereof in response to the pressure of said air whereby to unseat said valve.

5. In combination a mixing chamber of a carburetor, an open ended air inlet housing communicating therewith, a valve controltion.

FRED DAY. 

